In the field of biochemistry, sugar chains have attracted attention in recent years as a third type of chain following nucleic acids and proteins. In particular, research has been conducted on their involvement with cell differentiation and malignant transformation, immune response and fertilization, and attempts are continuing towards the development of new pharmaceuticals and medical materials.
In addition, sugar chains serve as receptors for numerous toxins, viruses and bacteria and are also attracting attention as tumor markers, and attempts are similarly continuing towards the development of new pharmaceuticals and medical materials in these fields as well.
However, although the importance of research on sugar chains is recognized, due to their complex structure and diversity, the pace at which this research has progressed is considerably slower in comparison with the first and second types of chains in the form of nucleic acids and proteins.
The objective of proceeding with this research is to develop various methods for purifying sugar chains. In addition, since numerous cases of sugar chains functioning as ligands for cell receptors have been confirmed rather than these sugar chains functioning independently, development has also proceeded on base materials for immobilizing various sugar chains to enable them to be used in analyzing sugar chain receptors (Patent Document 1, Patent Document 2).
Patent Document 1 indicates a method for producing a sugar chain array in which a sugar chain is bound to a first functional group, and a third functional group is bound to a chromophore by using a second functional group as a solid support. It is described in the examples thereof that a blocking procedure is carried out using bovine serum albumin in order to prevent non-specific adsorption following sugar chain immobilization. However, carrying out this blocking procedure following sugar chain immobilization is both complicated and troublesome.
On the other hand, Patent Document 2 describes a method for immobilizing a sugar chain on a base material through a spacer, and indicates that non-specific adsorption is inhibited by using a hydrophilic compound for the spacer. However, in this method, it is necessary to introduce an acetyl halide group into the solid support when immobilizing the sugar chain on the base material, and although this is comparatively easy in the case the material of the base material is glass, this method lacks versatility with respect to other materials.
In this manner, in addition to delays in the development of suitable techniques and base materials for immobilizing sugar chains, development has also been delayed with respect to sugar chain arrays on which sugar chains are immobilized that are useful for analyzing interactions between analytes and sugar chains.